1. Field of the Invention
This invention relates to a piezoelectric gas lighter in which the fuel gas is discharged and ignited in response to depression of a depression means, and more particularly to a structure for improving controllability and stability of action of a lock mechanism for disabling the depression means from being depressed in the piezoelectric gas lighter.
2. Description of the Related Art
In a piezoelectric gas lighter in which a valve mechanism and a piezoelectric unit are actuated in response to depression of a depression means (a control cap) so that fuel gas discharged from a gas discharge nozzle is ignited by a spark generated by the piezoelectric unit, there have been known various lock mechanisms which disable the depression means from being depressed to lock the lighter when it is not used and enable the depression means to be depressed in response to a lock release action when the lighter is to be used.
For example, U.S. Pat. No. 5,145,358 (will be referred to as xe2x80x9cthe first prior artxe2x80x9d, hereinbelow) discloses a lock mechanism in which a control cap is provided with a stopper member which is movable between its locking position where it prevents depression of the control cap and its releasing position where it permits depression of the control cap and is urged to the locking position, the stopper member being moved from the locking position to the releasing position by sliding an upper end portion thereof.
U.S. Pat. No. 5,885,069 (will be referred to as xe2x80x9cthe second prior artxe2x80x9d, hereinbelow) discloses a lock mechanism in which the whole control cap is movable about a piezoelectric unit between the locking position and the releasing position and a resilient portion for urging the control cap to the locking position is provided integrally with the control cap.
Further, U.S. Pat. No. 5,833,448 (will be referred to as xe2x80x9cthe third prior artxe2x80x9d, hereinbelow) discloses a lock mechanism in which a piezoelectric unit/control cap assembly is arranged to be rotatable between the locking position and the releasing position and the assembly is urged to the locking position by a separate resilient member.
However, the gas lighters provided with the lock mechanism in accordance with the first to third prior arts are disadvantageous in that the part for releasing the lock mechanism is small and hard to handle, the action of the lock mechanism is instable, or the control cap is moved to a direction different from the direction of depression of the control cap in response to the action of the lock mechanism, which makes it instable the ignition action, and that changes in components from the conventional volume products and incorporation of the components is complicated, which adds to the manufacturing cost of the lighters.
Specifically, in the lighter provided with the lock mechanism in accordance with the first prior art, since a lock member having a small control portion is provided to be slidable on a part of the surface of the control cap and the lock member is controlled, the lock releasing action is difficult and the normal ignition action is hard. Further, since a coiled spring for urging the lock member is disposed above the piezoelectric unit in the control cap, the position of the piezoelectric unit is changed from that in the conventional lighter without a lock mechanism, which results in many components to be changed and complicates incorporation of the spring.
In the lighter provided with the lock mechanism in accordance with the second prior art, since the whole control cap is moved about a piezoelectric unit between the locking position and the releasing position, depression of the control cap is apt to be instable and the engagement between the piezoelectric unit and the control cap becomes instable which weaken the integrality of the assembly.
In the lighter provided with the lock mechanism in accordance with the third prior art, since lock of the lighter is released by inclining the piezoelectric unit/control cap assembly, the position of the piezoelectric unit becomes assembly and the distance between the piezoelectric and the nozzle across which the spark is generated varies from ignition action to action, which deteriorates the igniting performance. Further, the structure exposes the gap between the control cap and the lighter body and permits foreign matters to enter the lighter body to obstruct the igniting action and the quenching action.
In view of the foregoing observations and description, the primary object of the present invention is to provide a piezoelectric gas lighter which can be manufactured at low cost without deteriorating the controllability of the lock mechanism, the stability in action and the igniting performance and with a less number of components to be changed from the conventional components.
In accordance with the present invention, there is provided a piezoelectric gas lighter comprising a lighter body in which fuel gas is stored, a fuel supply means which supplies the fuel gas in the lighter body to a nozzle through a valve mechanism, an actuator lever for opening and closing the valve mechanism, a spark ignition means which ignites the fuel gas discharged from the nozzle, and a depression means which actuates the actuator lever and the spark ignition means to open the valve mechanism and ignite the fuel gas discharged from the nozzle in response to depression of the depression means, wherein the improvement comprises that
the depression means comprises a control cap operatively connected to a piezoelectric unit, a stopper member which is movable between a locking position where a part of the stopper member is engaged with the lighter body to disable the control cap from being depressed and a releasing position where the stopper member is released from the lighter body to permit depression of the control cap and an urging member which urges the stopper member to the locking position, the stopper member is provided with a pair of sliding portions extending back and forth on opposite sides of the control cap and the sliding portions are slidably supported by the control cap so that the stopper member is movable downward together with the control cap and movable between the locking position and the releasing position, and the urging member comprises a pair of resilient pieces provided on opposite sides of the control cap so that they are engaged with the sliding portions of the stopper member to urge the stopper member in the locking position and the stopper member is moved from the locking position to the releasing position by urging the stopper member toward the control cap.
The urging member may be formed of a pair of resilient pieces of resin formed integrally with the control cap or may be formed of a pair of resilient pieces of resin or metal formed separately from the control cap.
The stopper member may comprise a peripheral wall which covers the opposite side surfaces and the rear surface of the control cap. Preferably, the stopper member is provided with a control portion which covers the upper surface of the control cap at least at a rear portion of the control cap.
Preferably, the control cap is provided with a hook portion which is engaged with a projection, which projects inward from the sliding portions of the stopper member, to limit the movement of the stopper member to the locking position.
In the gas lighter in accordance with the present invention, since the depression means is formed by a control cap, a stopper member and an urging member and the stopper member is provided with a pair of sliding portions which extend back and forth on opposite sides of the control cap and are slidably supported by the control cap so that the stopper member is movable downward together with the control cap and movable between the locking position and the releasing position, a part of the stopper member is in engagement with the lighter body to prevent depression of the control cap, thereby locking the lighter from being ignited, in the normal state where the stopper member is in the locking position, and when the stopper member is moved to the releasing position, the stopper member is disengaged from the lighter body to permit depression of the control cap.
After the gas lighter is ignited and the depression means is released, the depression means moves upward and at the same time, the stopper member is automatically moved to the locking position under the urging force of the urging member, thereby locking the lighter from being ignited.
Further, since the stopper member is separated from the control cap and the stopper member is moved relative to the control cap by virtue of the sliding portions and the resilient pieces, the lighter can be locked and released by a simple action of sliding the sliding portions back and forth relative to the nozzle, the locking action and the releasing action can be stabilized and the controllability of the lighter is improved. Further, by only changing the control cap of the conventional piezoelectric gas lighter without a lock mechanism, a piezoelectric gas lighter provided with a lock mechanism can be realized. That is, the lock mechanism can be incorporated in the conventional piezoelectric gas lighter without a lock mechanism without changing the relative positions between the components, such as the relative position between the piezoelectric unit and the nozzle, the manner of fixing the piezoelectric unit and the control cap and the movement of the piezoelectric. At the same time, the control cap is held stationery when the stopper member is moved between the locking position and the releasing position, and the piezoelectric unit and the control cap can be fixed together by fitting. Further, the control cap can be held by a windshield cap not to be drawn out in the vertical direction. Thus, a piezoelectric gas lighter with a lock mechanism which is stabilized in its igniting performance and igniting action can be manufactured at low cost.
Further, by disposing the resilient pieces on opposite sides of the control cap to be engaged with the stopper member and urge the same to the locking position, the lock mechanism can be incorporated without changing the relative position between the control cap and the piezoelectric unit, and the stopper member can be stably moved and urged to the locking position. Further, since the stopper member is moved from the locking position to the releasing position by urging the stopper member toward the control cap, lock releasing and ignition can be effected in a series of actions, which further improves controllability of the lighter. Especially when the urging member is formed by a pair of resilient pieces of resin formed integrally with the control cap or formed by a pair of resilient pieces of resin or metal formed separately from the control cap, incorporation of the depression means is facilitated and the manufacturing cost can be reduced.
When the stopper member is provided with a peripheral wall which covers the opposite side surfaces and the rear surface of the control cap, the stopper member is further stably moved between the locking position and the releasing position. When the stopper member is provided with a control portion which covers the upper surface of the control cap at least at a rear portion of the control cap, the area for operating the stopper member is enlarged and the operation of the stopper member is facilitated.